1. Field of the Invention
This invention relates to a device for actuating a cover for selectively closing an opening, in a surface which surrounds the cover, in a first position or for at least partially clearing the cover in the opening in a second position, and particularly, the cover forming the top in the opening in the roof of a motor vehicle, which roof forms the surface. The device includes the following elements:
a swiveling arm which extends from the front end to the back end of the cover and which is provided with means for attachment of the cover;
lifting means to produce a swiveling motion on the swiveling arm relative to the surface, and
drive means to apply force to the lifting means and to move the cover between the first and the second position.
The device is especially suited for actuating an adjustable cover in an openable roof of an automobile. The cover is movably attached on the roof of the auto by means of the device.
2. Description of Related Art
A device of the initially mentioned type is known from European patent 0 543 427. In it the cover is attached in a frame which is mounted around the opening in the roof. The cover is attached to two swiveling arms which are mounted on either side of the cover. The cover can be swiveled relative to the frame by means of these arms. The front end of each of the swiveling arms is hinged via a coupling arm to the front part of the drive slide. These slides can be pushed in a rail. On each of these slides moreover, on the respective back end, a lever is mounted which is hinged to the swiveling arm. When the cover is opened the drive slides are pushed in the back direction for example by means of a cable from the front end of the rail. In the first part of this motion, the cover swivels by means of the lever into a tilted position or lift position. In doing so, viewed in the direction of travel of the vehicle, the cover pivots around the front side so that the back side of the cover projects over the roof. A ventilation gap is formed between the back side of the cover and the roof. The roof is extended rearward by continued motion of the drive slides in the back direction. Since the swiveling arms and the levers are connected to the drive slides, these swiveling arms and levers are moved together with the cover mounted thereon overall (in the tilted position) in the back direction of the opening. This sliding motion clears the front part of the opening.
With open roofs of motor vehicles it is one objective for the ratio between the area of the opening in the roof (size of the cover) and the area which can actually be cleared (maximum opened position) to be as favorable as possible. In the case in which the cover can be moved over a relatively great distance, a relatively small opening can suffice to open the desired roof area. In one such favorable ratio between the size of the cover and the area actually to be opened in the device it is presupposed that the distance between the fulcrum of the lever with the drive slide as far as the fulcrum of the front end of the swiveling arm is kept as small as possible. This distance between the fulcrum on the front end of the swiveling arm and the fulcrum of the lever corresponds to the length of the section over which the cover is connected to the supporting guide rail (which is also called the support base of the device). The support base is important especially for the stability of the cover in the opened position. It should be clear that in the opened position the cover is exposed to considerable wind forces especially at higher speeds. To prevent the device from being bent or in some other way adversely affected under the influence of the forces exerted by the wind, the stability of the cover and the device which supports it must be as large as possible.
In the device claimed in the aforementioned European patent (""427) the desire is to clear the opening as far as possible, in contrast to the desire to keep the cover as stable as possible in the opened position.
The object of the invention is to devise a device in which a cover can be moved from a closed position into an opened position, and such that on the one hand the cover can be moved as far as possible in order to clear the opening as far as possible, while on the other hand providing relatively great stability to the cover during the entire movement of the cover.
This object is achieved in this invention by the swiveling arm having at least two elements which are connected to one another to be able to move or telescope, the front end of one of the elements being hinged via a fulcrum to the stationary part of the device or the surface.
This measure results in that the fulcrum of the swiveling arm is immobile relative to the base, i.e. the surface. This means that the swiveling arm, when the cover is being opened, does not move as a whole jointly with the cover relative to the surface, but that the swiveling arm increases its length when the cover is being pushed on. The lifting means, for example in the form of a lever, can move at the same time with the cover. The stationary fulcrum between the swiveling arm and the surface on the one hand and the fulcrum which is moving at the same time between the surface and the lifting means on the other hand results in that the length of the support base of the device increases while the cover is opening. This is advantageous for stability.
The angular torsion of the cover relative to the base is determined on the one hand by the length of the lifting means and on the other hand by the distance of the lifting means to the stationary fulcrum. In this way the angular torsion of the cover relative to the base will decrease when the cover is extended to the outside. In this way the wind resistance of the cover is increasingly reduced in the direction to its complete opening.
According to one preferred embodiment, it is possible for the swiveling arm to have an intermediate element which is movably connected on the one hand to the first element and which is movably connected on the other hand to a third element. In this embodiment, it is possible for the means for attachment of the cover to be attached to the third element.
This embodiment makes it possible for the cover to be attached to the rear element which is movably attached to the first or the intermediate element of the swiveling arm. It is thus possible for the freedom of motion of the cover to be further increased relative to the stationary fulcrum. The extreme position of the cover relative to the stationary fulcrum is not determined by the distance between the stationary fulcrum and the end of the second element or the distance between the stationary fulcrum and the lever. The cover can be pushed further out of the opening by the additional length which is offered by the third element. This makes it possible to clear the opening in the completely opened state over a relatively large area.
Furthermore, in another object of the invention, it is possible for the elements of the swiveling arm to be made as telescoping elements, the front element being connected to the first end of a flexible compression-tension element which is guided via a guide groove near the back end of the intermediate element to the attachment for the second end of the compression-tension element, which attachment is mounted on the third element.
The action of the compression-tension element results in that the rear element is similarly automatically moved relative to the front element when the intermediate element is moved relative to the front element. Since the compression-tension element extends from the front element via a guide groove in the intermediate element to the attachment on the rear element, when the intermediate element moves relative to the front element the rear element will move relative to the intermediate element, which movement is greater than the motion of the intermediate element relative to the front element. If the compression-tension element does not extend when the respective elements move or does not change its length in some other way, the rear element will move exactly twice as fast as the intermediate element. Thus considerable displacement motion of the cover can be produced by a short actuating path.
According to one advantageous embodiment, it is possible for the device to comprise a guide rail which extends in the lengthwise direction of the opening on its sides from the front end to the back end, the drive means being connected to the lifting means via a drive slide which can be moved in the guide rail between the front and the back end of the rail, and the lifting means being connected by the first end to the drive slide and by the second end to the swiveling arm. Here it is possible for the lifting means by its second end to be connected to the intermediate element and for the lifting means to comprise a lever, the lever being hinged by the first end to the drive slide and hinged by the second end to the intermediate element.
The drive slide and thus the lever coupled to it can be pushed together in the back direction for extending the roof. The maximally extended position is reached when the drive slide reaches the back end of the rail. In this position, the swiveling arm will be maximally extended. The rear element moving relative to the intermediate element yields a very favorable ratio between the surface of the cover and the extended part of the opening. Furthermore, the support base in the maximum position also will have the maximum length and thus a favorable effect on stability.
As set forth below, in the invention it is possible for the system to comprise a coupling arm which is hinged by the first end to the drive slide and by the second end to the intermediate element.
This measure makes it possible from the closed position for the drive slide to move first for a certain path relative to the intermediate element. In this section the drive slide will allow mainly the lever to rotate and thus the cover to swivel relative to the roof.
This invention is suitable especially for actuating the cover of an openable roof for a motor vehicle. But other covers are also possible, for example roof hatches on buildings, can be advantageously actuated with it.